/*
 * Copyright (C) 2004, 2005, 2006 Joe Walnes.
 * Copyright (C) 2006, 2007, 2008, 2009 XStream Committers.
 * All rights reserved.
 *
 * The software in this package is published under the terms of the BSD
 * style license a copy of which has been included with this distribution in
 * the LICENSE.txt file.
 * 
 * Created on 15. March 2004 by Joe Walnes
 */
package com.feilong.lib.xstream.core;

import com.feilong.lib.xstream.converters.ConverterLookup;
import com.feilong.lib.xstream.io.HierarchicalStreamWriter;
import com.feilong.lib.xstream.io.path.Path;
import com.feilong.lib.xstream.mapper.Mapper;

public class ReferenceByIdMarshaller extends AbstractReferenceMarshaller{

    private final IDGenerator idGenerator;

    public static interface IDGenerator{

        String next(Object item);
    }

    public ReferenceByIdMarshaller(HierarchicalStreamWriter writer, ConverterLookup converterLookup, Mapper mapper,
                    IDGenerator idGenerator){
        super(writer, converterLookup, mapper);
        this.idGenerator = idGenerator;
    }

    public ReferenceByIdMarshaller(HierarchicalStreamWriter writer, ConverterLookup converterLookup, Mapper mapper){
        this(writer, converterLookup, mapper, new SequenceGenerator(1));
    }

    @Override
    protected String createReference(Path currentPath,Object existingReferenceKey){
        return existingReferenceKey.toString();
    }

    @Override
    protected Object createReferenceKey(Path currentPath,Object item){
        return idGenerator.next(item);
    }

    @Override
    protected void fireValidReference(Object referenceKey){
        String attributeName = getMapper().aliasForSystemAttribute("id");
        if (attributeName != null){
            writer.addAttribute(attributeName, referenceKey.toString());
        }
    }
}
